April 12, 1945. After several years of a bloody conflict in Europe and the Pacific, America is stunned by news of the death of President Franklin D. Roosevelt. In an instant, Vice President Harry Truman—who had been sidelined from war planning and knew nothing about the ultra-secret Manhattan Project to develop the first atomic bomb in the world—must take command of a country fighting across multiple continents, and make one of the most important decisions in history. The author tells a gripping story of the turbulent months, weeks, and days leading up to August 6, 1945, when Truman orders the bomb to be dropped on Hiroshima.